Pneumatic barrel buffer for guns



- June24, 1947. LA, ANDERSON 2,422,767

PNEUMATIC BARREL BUFFER FOR GUNS Filed Aug. 26, 1943 v 2 Sheets-Shqet 1 4. M INVENTOR.

June 24,1947. A, ANDEgs 2,422,767

PNEUMATIC BARREL BUFFER FOR GUNS Filed Aug. 2.6,, 1943 i 2 Shuts-Sheet 2 $44; 4 INVHVTOR.

Patented June 24, 1947 Ge eral.- lvlet s= Corp a on. Daytsxm 1 194... n

nrnprati n tinnlaware Application-August 26, 1943; SElifll'NQ; 500M 5-Qlaims- (01. 89-1) 'I-hisinver-rtion relates to amufierand more perrticulaflyitoa-barreljbufler. for use one 50zca1iben Browning-machine gun.

At present; the-250 11111121 Browning machine: gun" is-.p-rovidedw-ith- :2 barrel: buffer. whereinithe bufilng: actionis producedby. a plunger movingthrough a-body-of oil; In.suchan arrangement;

the=temperature materiallyefl'eots-the rate-ofi'fire: and it frequently happens that some of theoil: leaks out withtheresult that thG-bHfiBrAS-nOne 1Q.

too dependable A'- large number ofbuffers have beendesignedadvantages:

Thusone objectofthisinvention isto providea buifer whioh is operable ata-lltemperatures and elevations normally encountereda Anotherobjeet' is toprovide an improved-barrel bufienwhich is comnletelyinterchangeable with the present oil buffers now inuseon 60 calibermachine guns.

Further obj ects-andadvantages of the present invention willbe apparent from the followingdescription; reference beinghad totheaccompanying drawings,- whereina preferred form of the present invention is clearlyshown.-

In' the drawings:-

Fig. 1 is afragmentary elevational view with parts broken away showing somewhat diagrammatically a standard machine gun provided with myimproved barrelbuffer;

Fig; 2= is alongitudinalseetional view through my improved barrel bufler;

Fig. 3'- is a view similar to-Fig. 2 showingthe position-of the parts when the barrel extension has moved toits rearmost position;

Fig. 4 is an end view of the buffer; and- Fi'g. 5'- is a sectionai' viewtaken on line 595 of'Fi 3.

Referring now to-Fig. 1 of the drawings, referenoe numeral [0 designates generally the breech housing of: a. standard 50 caliber Browningmachine gun. Reference numeral l2- designatesthe barmlofi the gun and reference numeral I4 design mates the-barrelrextension which-iiszmovable-along with the barrel "2 upon recoil. The barnel ex-v tensioni I4 is provided with a proiec iom (fi -wh h w 2.. inte lc kss th henotch- I n dpd. n het mpt en .-otthe1nlunge i 1 e'berr L- n er enerlly desi nat d rahee Q mnQe- HmQ eL-H, h rreil ufien 2 i x s neor ed b he ste iqnarylw erm- 2; hemstrusnmn i; hich-1 s h same as;

nr hernresen r nni 'Bhe Quten sheneensir izq-oir the; ba re buf er: 11-; imi nto; t e; hape nd.- s ze of h present ili rnetbufiemmii s mmn etelrintershene e lei e ew thlwithouk eitazinezeny of: thether. e n.- er.ts-.. Referen e: nume al; des nates a lrYfi li iQ lfidbpl fi bu e n riec by; e. nd: plate. 21 in. amord me; with iensier meme heholtrbufieriar'bee r hesflhendise ty qnow us dior tgmen e pith ther; q n mmr 16 t ne-suitab e for; stop in the-mevementofi he bolt:

Referring now to tie,- .linwh chthere eshonm e ecticneiviewr nmy mpm esl, utte smstmertiom. reierence nume a ibde nates he; ma n. cyliniierwithm; whi h a: 99s?" fi tin :B 9 1: 3 s: aria ciztom i me te. n r: m e mrturesr- 4e s rmvideshintheg zell flamesyl nde n. as sh wn- A. ssr en lement. 35,- be n- .nr@ isie i- 9r: Dre..- entine: orei n: pa ticl s; H1011}: enter n he y inder 311.: lxfiber hufierdiee flz s eeuredfie he. mner nci we f:: h;5. .n1 -3; t rivet 4H.-

nistsm 3 eneect s o plunger aibymeensz iy em: .2; ar ied: dir tl by. themstnnilh heme :2 mseej h pu h n. lon ated: slot A; pr vided; he en arged nne nsl-of: as mown ume-muted: ot, time; f ost: motion c nneq ien b tw en hemuns isenslin e onflp A ent 5 is ryrq isiest or: he al ne chamber at A p n f. wh t h sim lan-to: th c esmnsi p ng now used. n; the oiiz nfie bi s s he plun e i a d' t e pist n 311 nto. he po it on n which hey a e shown in Fig. 2. 'lfheoneendofthe spring abuts a ainst a. guiee-waeher- 51- hic s.- dent alf desi n to; he qrre n ndine g id wash rs; new. us d-9 heoilbufi r- A... pin ca ried by he n un er- Pos ions theeuide washer v la iy o the plu er.- 'Bhe wash is-rrov d d w th upstand ng; ues..5 -2sple ed: n m ite id s o he 9. 0 as shown The filla km lfimlm 54- .5 Pre iew:- n. the uide washe ind: m v s he usual. euisie l (not shown rov ded n he ment 2.2.- so as to prev n he n un er i; rom rotat n Inasmunh: a he lug 5.4 is d nt paln nstruction-end perati ntp. a qor-msn ndin i u ncw-usedaon he l buff tn qs .9 ur he er pti n or; xelamtion; as tspnst m en d; o e ation. we we ikm mem ntifi h lds the.- naltts assembled and; lso imit the; QPQ Q- movement of the piston 32 and the plunger 18. A pair of vent holes 58 have been provided in the element 56 as shown.

A plurality of bowed spring washers 60 are placed within the chamber 8| provided within the piston 32 as shown, These spring washers are of the type commonly known as Belleville washers. The washers 60 do not begin to compress until the piston is almost at the end of its stroke. A valve port 62 is provided at the inner end of the piston 32. The port 62 is normally closed by the valve 64 which is biased to the closed position by means of a spring 66. The valve 64 and spring 66 are held in place by the element 68 which is constructed as shown in Figs. 2 and 3. The valve 64 is intended to open only in case excessive pressures are developed within the main compressionchamber 10. This valve, therefore, is primarily a safety valve.

By virtue of the above described arrangement, upon recoil of the gun barrel and the barrel extension 14, the plunger 18 very'rapidly moves to the rear and carries along with it the piston 32 which then compresses the air within the chamber 10. No relative movement takes place between the piston 32 and the plunger I8 until the air pressure within the chamber 10 is great enough to cause the Belleville washers 60 to be compressed. Compression of the washers 60 causes relative movement to take place between the plunger 18 and the piston 32.

Enough clearance is provided between the piston 32 and the cylinder 30 so that slow movement of the piston 32 within the cylinder 30 such as produced while hand cooking the gun merely causes the air in chamber 10' to leak past the piston rather than be compressed to any appreciable extent, but the clearance is not great enough to prevent the air being compressed upon a normal recoil of the gun barrel. I have found that a clearance of .0007 inch is satisfactory. The fiber washer 38 is provided merely to absorb the final energy of recoil in the event that all of the energy is not absorbed by the compression of air and compression of the Belleville washers 60.

At normal atmospheric pressures, th piston 32 seldom, if ever, strikes the fiber disc 38 a very hard blow whereas at high altitudes the fiber disc 38 may be required to absorb a small amount of energy each time the buffer operates, since less air by weight is Present in the compression chamber 10.- The Belleville washers 60 are preferably designed so as not to come into action until towards the very end of the compression stroke when the air in the chamber 10 is highly compressed. The compressed air, the Belleville washers 60 and the spring 46 all assist in returning the gun barrel to its forward position.

By virtue of the above described construction, changes in temperature and elevation have very little effect upon the operation of the buiIer. Once the buffer leavesthe factory it requires no further adjustment and is completely interchangeable with the existing oil buffers now in use. Furthermore, the buffer does not materially interfere with hand cooking of the gun since the air leaks past the piston fast enough not to interfere with hand cooking and the gun may be cocked without compressing the washers 60. However, at normal recoil speeds, the buffin action begins almost immediately and the resistance oiiered by the buifer to the recoil of the barre] and barrel extension gradually increases as the plunger l8 goes to the rear. Obviously the above described construction is very simple and inexpensive to manufacture, is not subject to breakage, and overcomes the disadvantages of the present oil buffer.

While I have shown the bufier used as a barrel buffer in a .50 caliber Browning machine gun it is obvious that it could be used in other applications.

While the form of embodiment of the invention as herein disclosed constitutes a preferred form, it is to be understood that other forms; might be adopted, as may come within the scope; of the claims which follow:

What is claimed is as follows:

1. In a rapid firing gun; a breech housing; a barrel; 9. barrel extension within said breech:

housing; a, pneumatic barrel buffer arranged toabsorb energy of recoil of sai barrel and barrel extension; said bufier comprising a stationary cylinder, a hollow piston within said cylinder,. a piston operating plunger slidably extendin into= said hollow piston, spring means within said hol-- low piston pushing outwardly on said plungen; means carried by said piston for limiting the out-- ward movement of said plunger, said plunger.- connecting said barrel extension and said piston. spring abutment means adjacent the front end. of said plunger, spring abutment means on the: front end of said cylinder, and a compression; spring between said first and second named abut--- ments for biasing said piston into its forward": position in said cylinder, said piston having a. substantial clearance within said cylinder where by said bufier oifers less resistance to slow move-- ment than to rapid movement of said barrel and barrel extension.

2. In a rapid firing gun, a breech housing, a. barrel, a barrel extension within said breech nous-- ing, a pneumatic buffer arranged to absorb energy of recoil of said barrel and barrel extension, said. buffer having piston means operating within a.

cylinder for compressing a body of gas, said piston having a substantial clearance within said.

cylinder, and a resilient connection between said. piston and said barrel extension, said connection. being such that it will not be substantially com-- pressed until after the gas has been substantially compressed, said resilient connection comprising: a plurality of Belleville washers disposed within: said piston.

3. In a rapid firing gun. a breech housing, a barrel, a barrel extension within said breech housing, a pneumatic bufier arranged to absorb energyof recoil of said barrel and barrel extension, said buifer having piston means operating within a cylinder for compressing a body of gas, and a resilient connection between said piston and said barrel extension, said connection being such that it will not be substantially compressed until after the gas has been substantially compressed, said piston having a, substantial clearance within said cylinder whereby said buffer oilers less resistance to slow movement of said barrel extension than to rapid movement of said barrel extension, and a fiber buffer disc between said piston and the end of said cylinder.

4. In a rapid firing gun. a pneumatic barrel buifer adapted to absorb energy of recoil of a gun barrel and barrel extension comprising in combination, a stationary cylinder, a hollow piston within said cylinder, a piston operating plunger slidably extending into said hollow piston, spring means within said hollow piston pushing outwardly on said plunger, means carried by said piston for limiting the outward movement of said plunger, said plunger connecting said barrel extension and said piston, spring abutment means adjacent the front end of said plunger, spring abutment means on the front end of said cylinder, and a compression spring between said first and second named abutments for biasing said piston into its forward position in said cylinder, said piston having a substantial clearance within said cylinder whereby said bufier offers less resistance to slow movement than to rapid movement of said barrel and said barrel extension.

5. In a rapid firing gun, a pneumatic barrel bnfier adapted to absorb energy of recoil of a gun barrel and barrel extension comprising in combination, a stationary cylinder. a hollow piston within said cylinder, a piston operating plunger slidably extending into said hollow piston, spring means within said hollow piston pushing outward- 1y on said plunger, means carried by said piston for limiting the outward movement of said plunger, said plunger connecting said barrel extension and said piston, spring abutment means adjacent the front end of said plunger, spring abutment means on the front end of said cylinder, a fiber buffer disc disposed within said cylinder between said piston and the end wall of said cylinder for compression by said piston, and a compression spring between said first and second named abutments for biasing said piston into its outer position in said cylinder, said piston having a substantial clearance within said cylinder whereby said bufler offers less resistance to slow movement than to rapid movement of said barrel and barrel extension, said cylinder having a vent opening arranged to equalize the pressure within said cylinder and outside of said cylinder at the beginning of each compression stroke of the piston.

LOUIS A. ANDERSON.

REFERENCES CITED The following references are of record in the file of this patent:

Maxim Sept. 23, 1890 

